The present invention relates to an optical switch, an optical amplifier and an optical power controller as well as an optical add-drop multiplexer.
Accordingly, it is an object of the present invention to provide a novel optical switch free from the above problems.
It is a further object of the present invention to provide a novel optical amplifier.
It is a still further object of the present invention to provide a novel optical power controller.
It is yet a further object of the present invention to provide a novel optical add-drop multiplexer.
The first present invention provides an optical switch including the following elements. At least a plurality of optical transmission lines are provided for transmissions of optical signals. Each of the at least plurality of optical transmission lines have at least an impurity doped fiber. At least an excitation light source is provided for emitting an excitation light. At least an excitation light switch is provided which is connected to the excitation light source and also connected to the at least plurality of optical transmission lines for individual switching operations to supply the excitation light to the at least plurality of optical transmission lines to feed the excitation light to the impurity doped fiber on the at least plurality of optical transmission lines, thereby causing an excitation of the impurity doped fiber on selected one of the at least plurality of optical transmission lines so as to permit a transmission of the optical signal through the excited impurity doped fiber, whilst unselected one of the impurity doped fibers is unexcited whereby the optical signals are absorbed into the unselected one of the impurity doped fibers thereby to discontinue transmission of the optical signal by the unselected one of the impurity doped fibers.
The above and other objects, features and advantages of the present invention will be apparent from the following descriptions.